What would be a better material for this?

[sheetmetalworker]

I just found a couple of notes and the better results were using baffles and a ceramic glass fibrewool, and also a test .410 bore had a silencer outside bore of 44mm and a length of 270mm!! however this data is years old and something better will exist by now im sure, ive witness a ,223 recently that was absoutley silent except for a 'click', fascinating stuff really, and a market there for somebody im sure.

 

[hareng]

I think you have two options there Andy, you can leave as is or open out the front baffles before fitting.
As you know the shot tapers outwards after leaving the barrel or it could be an alignment true to the bore issue.

I know about rim, centrefire and air rifle moderators/silencers they all act different depending upon the speed of gas or air going through them, same as muzzle breaks they can be made or designed to counteract the characteristics of the firing cycle.

Same old ideas from manufacturers with fundamental differences in build i am afraid as over 20 years ago. New apparent ground breaking developments are sales patter, whats described as new is old hat with different spacings, material/s and or build.
A bigger company copies design of small one man band, maufactures and calls it their own then another copies and so on before you know it inventor could have been a millionair within 10 years as something like 40% of air rifles are like that now.

Every object has a sonic signature so using cartridges or bullets from same manufacturer and different guns shouldnt be a difference. ie faster speeds, and more powder will have a different signature and more blast to control.
.223 will be breaking sound barrier so no cannot be supressed it can only quieten the blast. Speed of sound 1150ft/sec and gives a sonic crack that cant be tamed. However they can be made to tame the firing cycle ie .338 Lapua Magnum with 300 grain slug at 2750ft/sec down to recoil of an average .243, i do have a piccy from 8 years ago.